Lasting antibody and T cell responses to SARS-CoV-2 in COVID-19 patients three months after infection.

The dynamics, duration, and nature of immunity produced during SARS-CoV-2 infection are still unclear. Here, we longitudinally measured virus-neutralising antibody, specific antibodies against the spike (S) protein, receptor-binding domain (RBD), and the nucleoprotein (N) of SARS-CoV-2, as well as T cell responses, in 25 SARS-CoV-2-infected patients up to 121 days post-symptom onset (PSO). All patients seroconvert for IgG against N, S, or RBD, as well as IgM against RBD, and produce neutralising antibodies (NAb) by 14 days PSO, with the peak levels attained by 15-30 days PSO. Anti-SARS-CoV-2 IgG and NAb remain detectable and relatively stable 3-4 months PSO, whereas IgM antibody rapidly decay. Approximately 65% of patients have detectable SARS-CoV-2-specific CD4+ or CD8+ T cell responses 3-4 months PSO. Our results thus provide critical evidence that IgG, NAb, and T cell responses persist in the majority of patients for at least 3-4 months after infection.

Nosocomial cross-infection of hypervirulent Listeria monocytogenes sequence type 87 in China.

BACKGROUND: To investigate the epidemiological and phenotypic characteristics and molecular relatedness of L. monocytogenes, which were cultured from the blood and cerebrospinal fluid (CSF) samples isolated from two neonates. METHODS: In the present case study, two infected neonates were interviewed and epidemiological investigation performed. The phenotypic characteristics and molecular relatedness of L. monocytogenes was characterized by serotyping, pulsed-field gel electrophoresis and whole-genome sequencing (WGS). RESULTS: The field investigation found that the two neonates were born in the same hospital (Hospital B) and admitted to the neonatal department through different channels within half an hour by different nurses, where they were weighed and placed in different but adjacent incubators. Then they were cared for by the same group of nurses that evening. It is worth noting that there was no record of sanitation of the neonatal incubator of neonate-1. The serotype of the two isolated L. monocytogenes were 1/2b, with an indistinguishable pulsotypes and were sequence type (ST) 87. WGS showed that there were no core SNP differences identified. In order to explore the genomic traits associated with L. monocytogenes virulence genes, we identified the Listeria pathogenicity island 4 and found that the genome was devoid of any stress islands. There are no positive results from the environmental samples. Considering the genomic data together with epidemiological evidence and clinical symptoms, insufficient surface cleaning along with the nursing staff caring for these neonates was considered as cross-infection factors. CONCLUSIONS: To our knowledge, this is the first report of a nosocomial cross-infection of L. monocytogenes ST87 between two neonates, which carries the recently identified gene cluster expressing the cellobiose-family phosphotransferase system (PTS-LIPI-4) between two neonates. The test results of environmental samples in the hospital indicate that strict sterilization and patient isolation measures cannot be emphasized enough in neonatal nursing.

Transmission Potential of Asymptomatic and Paucisymptomatic Severe Acute Respiratory Syndrome Coronavirus 2 Infections: A 3-Family Cluster Study in China.

Data concerning the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in asymptomatic and paucisymptomatic patients are lacking. We report a 3-family cluster of infections involving asymptomatic and paucisymptomatic transmission. Eight of 15 (53%) members from 3 families were confirmed with SARS-CoV-2 infection. Of 8 patients, 3 were asymptomatic and 1 was paucisymptomatic. An asymptomatic mother transmitted the virus to her son, and a paucisymptomatic father transmitted the virus to his 3-month-old daughter. SARS-CoV-2 was detected in the environment of 1 household. The complete genomes of SARS-CoV-2 from the patients were > 99.9% identical and were clustered with other SARS-CoV-2 sequences reported from China and other countries.

Spatio-temporal evolution on geographic boundaries of HFRS endemic areas in Shandong Province, China.

OBJECTIVE: To take effective strategies and measures for the prevention and control of hemorrhagic fever with renal syndrome (HFRS) endemic areas by investigating its dynamic geographical boundaries in Shandong Province, China. METHODS: The incidence of HFRS from 1982 to 2008 in Shandong Prvince, China, was detected with inverse distance weighting (IDW) interpolation based on geographical information system (GIS). Dynamic geographical boundaries of HFRS endemic areas in Shandong Province, China, were analyzed by geographical boundary analysis. RESULTS: The HTN-type endemic areas of HFRS were located in Linyi City in phase 1 (1982-1986), the SEO-type endemic areas of HFRS were located in Jining City in phase 2 (1987-2003), and the endemic areas of HFRS in Jining City gradually disappeared and the endemic areas of HFRS with mixed-types of reservoir rodents were located in Linyi City in phase 3 (2004-2008). Meanwhile, new endemic areas emerged in the northwestern Shandong province, China. CONCLUSION: The SEO-type endemic areas of HFRS are located in western Shandong Province, China, and the HTN-type endemic areas of HFRS are located eastern Shandong Province, Chin, indicating that the endemic areas of HFRS should be vaccinated and rodents should be controlled.

[Prevalence and related risk factors on smoking among pupils in Shandong province].

OBJECTIVE: To study the prevalence of smoking and its influential factors among pupils in Shandong. METHODS: A multi-stage stratified-cluster random sampling method was used in the survey. 6050 students from 3 different cities of Shandong province were selected as the study population. A self-administered anonymous questionnaire was designed and the survey was conducted by trained investigators. RESULTS: The rate of attempting smoking among pupils under study in Shandong province was 6.0% while the current smoking rate was 1.2%. The average age of children who initiated smoking cigarette was 7.8±2.1 with 80.5% of them due to curiosity. 34.7% of them got the cigarettes from their families. In terms of the motivation of buying cigarettes, 74.3% of them claimed that the access to purchase was easy. Data from multivariate unconditional logistic regression analysis showed that the smoking behavior of pupils was influenced by their familial or surrounding environments. CONCLUSION: Tobacco control programs on pupils should be strengthened with more powerful control measures including health education.

[Mutation of drug resistant gene in HIV/AIDS patients with antiretroviral therapy in Shandong province in 2011].

OBJECTIVE: To investigate drug resistance status in patients with highly active antiretroviral therapy (HAART) in Shandong province. METHODS: A total of 758 patients were separated from the anticoagulatory whole blood during May and October in 2011. The entire protease gene and part of the reverse transcriptase gene were amplified by RT-PCR and nest-PCR in the samples with viral load larger than 1000 copies/ml, then sequenced the gene fragments. Mutation of drug resistant gene and drug susceptibility was analyzed by the online tool HIV db program developed by Stanford University. RESULTS: The rate of virologic failure in patients was 9.1% (69/758). A total of 53 gene sequences that acquired were used for genotypic resistance analysis. A total of 23 patients were indicated drug resistance with the total of 3.1% (23/742). Drug resistance rates of nucleotide reverse transcriptase inhibitor (NRTI) and non-NRTI(NNRTI) were 2.4% (18/742) and 3.0% (22/742), respectively, and the primary mutation types of drug resistance were M184V and Y181C for NRTI and NNRTI, with no resistance to protease inhibitor (PI). In the 23 patients indicated drug resistance, 78.3% (18/23) were NRTI resistance, 95.7% (22/23) were NNRTI resistance and 73.9% (17/23) dual NRTI and NNRTI resistance. CONCLUSION: The presence of drug resistant gene in HIV strains among AIDS patients with HAART in Shandong province was at low level, but mutation diversity was found in drug resistant gene.

Spatial structure of rodent populations and infection patterns of hantavirus in seven villages of Shandong Province from February 2006 to January 2007.

BACKGROUND: Hemorrhagic fever with renal syndrome (HFRS) is endemic in Junan county, Shandong Province, China. We conducted geographic information system (GIS)-based spatial analysis with the objective of estimating the spatial distribution of rodent populations and their hantavirus infection patterns, to describe the spatial relationships of hantavirus strains in small ecological areas and to identify key areas in endemic areas of HFRS for future public health planning and resource allocation. METHODS: Rodent sampling was conducted in seven villages in Junan county from February 2006 to January 2007 using field epidemiological surveillance. Dynamics of hantavirus infection and population densities in rodents were investigated. Spatial statistical techniques including Ripley' L index and nearest neighbour hierarchical (NNH) clustering analysis were conducted to reveal the spatial structure of rodent populations in seven villages. Phylogenetic analysis and two-dimensional minimal spanning tree (2-D MST) models were employed to describe the spatial relationship of hantavirus strains. RESULTS: Data showed that Mus musculus was the most common species in our study area, followed by Rattus norvegicus. Ripley's L index and NNH analysis showed that the spatial distribution of all captured rodents, Mus musculus and Rattus norvegicus in seven villages were clustered and there were hotspot areas of rodent distribution. The branches of 2-D MSTs had similar topologies to those of corresponding phylogenetic trees, and hantavirus strains exhibited obvious connective traces in seven villages. CONCLUSIONS: These results contribute to the understanding of the spatial distribution of rodent populations and hantavirus infection patterns in small areas, and identify priority areas within the epidemic areas for the development of a better prevention strategy against hemorrhagic fever with renal syndrome in a small ecological area.

[Analysis of condom use and its factors on female sex workers in Shandong province].

OBJECTIVE: This study was to investigate the condom use and its factors on sex workers in Shandong province, and to provide effective suggestions for AIDS prevention strategies and interventions. METHODS: From April to July in 2009, 4732 female sex workers were investigated through anonymous questionnaires from 11 cities which were selected based on the AIDS epidemic, geographic location, economic conditions in Shandong province. Serum samples were collected and antibodies were tested by ELISA and TPPA from 4641 people. RESULTS: 4732 female sex workers who were 15 - 58 years old were investigated and the majority belonged to the low age group (≤ 24 years old) which accounted for 61.5% (2912/4732). Among the 4732 female sex workers, the unmarried, the divorced, or the widowed females accounted for 72.8% (3441/4725) and 72.0% (3403/4726) of them were poorly educated.42.3% (1994/4719) of them were found from other provinces. The right answers for knowledge of AIDS accounted for 45.7% (2164/4732). 80.6% (3416/4236) of these females were found to used condoms in the most recent commercial sex activity. The rate of consistently using condoms in sex activity during the last month was 58.4% (2467/4221). In this survey, 7.3% (337/4637) of investigated females had been diagnosed with sexually transmitted diseases, 30.7% (1449/4726) of them had received HIV antibody test, 70.4% (3323/4732) of these people had received the AIDS intervention services, and 3.6% (167/4668) of them had ever used drug. Multivariate logistic regression analysis showed that high education level (junior high school or lower vs senior high school or higher, adjusted OR = 0.77, 95%CI: 0.67 - 0.90), having received the HIV intervention (received vs unreceived, adjusted OR = 1.36, 95%CI: 1.17 - 1.58), antibody detection (done vs not done, adjusted OR = 1.33, 95%CI: 1.15 - 1.55), and good knowledge about AIDS (low score group vs high score group, adjusted OR = 0.37, 95%CI: 0.32 - 0.44) were independent factors that increased safe sex behavior; while using drug (drug vs not drug, adjusted OR = 0.22, 95%CI: 0.15 - 0.31) was a negative factor. CONCLUSION: The prevalence rate of HIV infection among female sex workers was low in Shandong province. However, the low rate of condom use and the high prevalence of self-reported STD-related symptoms suggested that more attentions should be paid to the factors of risk behaviors, and more targeted interventions are critically needed.

[The prevalence and evolution of HIV drug-resistant strains in people who live with HIV/AIDS during HIV antiretroviral therapy in Shandong province].

OBJECTIVE: To understand the prevalence and evolution of HIV drug-resistant strains in people who live with HIV/AIDS (PLWHA) during HIV antiretroviral therapy in Shandong province. METHODS: Viral load testing was performed by using fluorescence real-time quantitative PCR (NucliSens EasyQ system) on 324 patients who were under HIV antiretroviral therapy (ART) over 1 year in Shandong province. HIV resistance testing was conducted on the samples with more than 1000 copies/ml by using genotypic resistance testing method established in our lab. We tested the samples from drug-resistant patients before and after treatment to analyze the evolution of HIV resistant strains. RESULTS: The resistance rate for the patients under HIV ART over 1 year was 6.2% (20/324). The rate of drug-resistant mutation, but not resistant to ART was 0.6% (5/324). Nucleoside reverse transcriptase inhibitor (NRTIs) and non-NRTIs (NNRTIs) accounted for 93.1% (94/101) and protein inhibitors (PIs) accounted only 6.9% (7/101) of all mutations. M184V (48.0%, 12/25) and Y181C (32.0%, 8/25) were the most frequent mutations among 25 samples. Our research showed 20.0% (2/10) patients were resistant to primary ART and 1 patient was detected drug resistance in 6 months after ART treatment. HIV evolved from wild type to drug resistant virus, from low level to high level drug resistance, and from resistance to few to multiple drugs. In addition, interactions between mutations may influence the sensitivity of patients to other drug treatment. CONCLUSION: The prevalence of HIV drug-resistant strains in Shandong province is still at a low level, but its evolution is complex.